Translations:Rust installation special notes in China/5/en

[source.ustc] registry = "https://mirrors.ustc.edu.cn/crates.io-index" RUSTUP_DIST_SERVER=https://mirrors.tuna.tsinghua.edu.cn/rustup [source.crates-io] replace-with = 'tuna'
 * Tsinghua Open Source Mirror (https://mirrors.tuna.tsinghua.edu.cn/)